The present invention relates to a method and a device for extracting vapors in an injection molding machine.
It is known to use injection molding machines in so-called clean rooms for producing clean and sterile plastic products. This is of particular interest in the medical field. For this purpose, either the entire injection molding machine or at least the mold unit is arranged inside a clean room or a clean room cell. The goal is hereby to directly produce clean parts which can also be packaged in a clean and sterile condition. During the injection molding process itself—and also after the parts are de-molded from a mold—the injection-molded parts per se out in a clean and sterile manner, because the injection-molded parts are automatically disinfected by the high processing temperatures in excess of 200° C.
However, the initially clean and sterile produced product can be contaminated by the environment after the parts are ejected or removed and until the parts are packaged. These contaminants are frequently generated by the operation, in particular the movement, lubrication and the drives of an injection molding machine. Particle emissions can thereby be released, which contaminate the clean room and consequently also the product. The effects from contaminants can be reduced by specific structural measures at the injection molding machine, thus generally allowing the production of plastic parts under clean conditions in a clean room or in a clean room cell.
However, the time of the startup of the injection molding machine still remains problematic. It is frequently necessary to first purge and remove the old material remaining in the plasticizing or injection unit before transitioning to the actual production operation for producing the parts and products. However, it is frequently not possible to introduce such material into an injection mold in order to thereafter dispose of the first parts. Depending on the material and on the complexity of an injection mold, the material must be purged, when the injection nozzle is lifted from the mold or the platen, through the injection nozzle into the environment and, for example, into a catch container. Such purge process may be required, for example, when a mold is changed. Unlike in a normal production operation, the material then does not vanish in the mold, but is instead collected in the catch container as a steaming hot material. The material then emits a large number of dirt particles when cooling down, which significantly contaminate the clean room. Although this may not cause a problem for the desired production, these contaminants in the clean room can still adversely effect to the quality of parallel productions on a different machine in the same clean room. For example, if the contamination level of the clean room is monitored online, then the clean room would be identified as contaminated in an aforedescribed purge process. The entire production on all parallel machines may then have to be disposed of as waste.
It is an object of the present invention to provide a device and a method for efficiently eliminating the aforementioned disadvantages.